Effect of additives and optimized Cyclic voltammetry parameters on the morphology of electrodeposited Tellurium thin film

Abstract

• The CV curve of Tellurium shifts with increasing deposition time. • Mechanism of Tellurium displacement and effect of additives. • Dense Tellurium film was fabricated under optimized deposition potentials. • Various dendritic morphologies of Tellurium were obtained by different additives. Thin film technologies in terms of preparation and fabrication are of great importance in various fields, such as integrated circuits (IC), LCD monitors, photovoltaics, solar cells and sensors. Tellurium, as a narrow bandgap semiconductor, has attracted much attention due to its rich optical and electrical properties. Taking advantage of these properties, its films have been explored in recent years as saturable absorbers, gas sensors, and thermoelectric materials. However, it is challenging to control the growth of the specific morphology of tellurium films. In this work, based on the electrodeposition challenge, we systematically investigated the electrodeposition process of tellurium films. It was found that the CV curves of electrodeposited tellurium shift in the positive direction with increasing deposition time. In addition, the stabilized potential was determined based on the stable deposition peak potential after a certain deposition time. Moreover, three different additives, namely polyvinyl alcohol (PVA), tartaric acid (TA) and sodium lignosulfonate (SLS), were adopted to manipulate the morphology of as-deposited tellurium films. A rational route to deposit tellurium films with various morphologies have been established.